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Hurricane Douglas Forecast Discussion Number 10
2020-07-22 22:39:10| National Hurricane Center (East Pacific)
Issued at 1100 AM HST Wed Jul 22 2020 000 WTPZ43 KNHC 222039 TCDEP3 Hurricane Douglas Discussion Number 10 NWS National Hurricane Center Miami FL EP082020 1100 AM HST Wed Jul 22 2020 Douglas's structure has continued to improve, with a more well-defined eye becoming apparent in visible and microwave satellite images. Subjective Dvorak intensity estimates from TAFB and SAB range from T4.0/65 kt and T5.0/90 kt, while the latest UW-CIMSS ADT is 4.0. Douglas's initial intensity is therefore raised to 70 kt as a blend of the satellite estimates. The hurricane has begun to gain some latitude, and the initial motion is just north of due west, or 275/14 kt. The track forecast reasoning has not changed since earlier this morning, with a persistent mid-tropospheric ridge to Douglas's north expected to be the main driving force for the entire 5-day forecast period. Douglas is forecast to turn west-northwestward by this evening, and then maintain that heading with some increase in forward speed through day 4 as it approaches the Hawaiian Islands. A bend back to the west is then expected at the end of the forecast period. The new NHC track forecast lies right along the forecast path from the previous advisory through 60 hours, although it has been shifted slightly north on days 3-5 based on an overall shift of the guidance envelope at those times. Confidence in the track forecast at this stage is rather high. Intensity-wise, low shear and sea surface temperature of 28-29C favor continued strengthening, potentially at a rapid rate for the next 24 hours. SHIPS, HCCA, and the Florida State Superensemble all bring the intensity near or at major hurricane strength in 24-36 hours, which qualifies as rapid intensification. The NHC intensity forecast is in line with these models and lies near the upper bound of the guidance envelope given the favorable conditions. Some weakening is expected to begin by 48 hours due to cooler waters, but since vertical shear is not expected to increase until around day 4, the weakening rate is likely to be gradual. This forecast increases the chance that Douglas could maintain hurricane intensity as it approaches the Hawaiian Islands, and all interests on the islands should monitor the forecasts as they evolve over the next few days. Key Messages: 1. Douglas is expected to move near or over portions of the Hawaiian Islands this weekend, and there is an increasing chance that strong winds and heavy rainfall could affect portions of the state beginning on Sunday. Interests on the Hawaiian Islands should continue to monitor the progress of Douglas and the official forecasts as they evolve over the next few days. FORECAST POSITIONS AND MAX WINDS INIT 22/2100Z 12.1N 130.9W 70 KT 80 MPH 12H 23/0600Z 12.7N 132.9W 85 KT 100 MPH 24H 23/1800Z 13.8N 135.8W 100 KT 115 MPH 36H 24/0600Z 15.1N 138.9W 100 KT 115 MPH 48H 24/1800Z 16.4N 141.9W 90 KT 105 MPH 60H 25/0600Z 17.6N 145.0W 80 KT 90 MPH 72H 25/1800Z 18.7N 148.0W 75 KT 85 MPH 96H 26/1800Z 20.0N 154.0W 65 KT 75 MPH...NEAR HAWAII 120H 27/1800Z 21.0N 160.0W 55 KT 65 MPH...NEAR HAWAII $$ Forecaster Berg
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Category:Transportation and Logistics